Characteristics of chip formation in micro V-grooving using elliptical vibration cutting

The chip and burr formation in micro V-grooving using elliptical vibration cutting (EVC) was investigated. Elliptical vibration of the cutting tool was achieved by employing two parallel piezoelectric actuators excited with two sinusoidal voltages of 90° phase difference. Changes in the shape of the chip and the cutting force, and the surface texture in micro V-grooving with EVC were investigated. It was observed that the reversal of the direction of the frictional force and the marked increase in the shear angle, which are two major characteristics of the EVC process, changed the shear flow inside the chip and reduced the cutting force, the chip thickness and the radius of curvature of the chip. When the excitation frequency of the tool was increased to an ultrasonic frequency of 65 kHz, more pronounced characteristics of EVC were observed. The cutting force in micro V-grooving with EVC at 65 kHz was reduced to approximately 10% of the cutting force magnitude under ordinary cutting. Low cutting force in the EVC process suppressed plastic deformation on the workpiece, thereby creating a micro V-groove free of burrs, which contributed to significant improvement in the form accuracy of a micro V-groove.